GaN or other III-N semiconductor based electronics and optoelectronics need low cost and scalable substrates. GaN or other III-N semiconductors grown on a silicon substrate is generally considered to be the most cost efficient technology. However, it is known that growing a III-N material, such as GaN, on a silicon substrate is difficult due in large part to the large crystal lattice mismatch (−16.9%) and the huge difference in thermal expansion coefficients (56%) between silicon and GaN. Also, final tinsel stress arises during III-N growth on Silicon and subsequent cooling of the structure. Thus, some type of buffer layer or layers is generally formed on the silicon substrate and the III-N material is grown on the buffer layer.
Generally, the prior art buffer layers, such as an AlN buffer, do not adequately reduce the strain in the silicon substrate or the III-N due to crystal lattice mismatch. In the prior art, various attempts are disclosed for the growth of different devices including III-V materials on silicon and other substrates. In some copending United States Patent Applications rare earth nitrides and rare earth oxy-nitrides are used in buffer layers, all of which are at least partially successful. Some specific applications and patents include: (A31) entitled “Rare Earth Oxy-Nitride Buffered III-N On Silicon”, Ser. No. 13/196,919, filed on Aug. 3, 2011; (A41) entitled “Nucleation of III-N On REO Templates”, Ser. No. 13/845,426, filed on 03/18/2013; (A62) entitled “Modification Of REO By Subsequent III-N EPI Process”, U.S. Pat. No. 8,501,635, issued Aug. 6, 2013; (A65) entitled “III-N Material Grown On REN Epitaxial Buffer On Si Substrate”, Ser. No. 13/939,721, filed on Jul. 11, 2013; and (A67) entitled “REN Semiconductor Layer Epitaxially Grown on REAlN/REO Buffer on Si Substrate”, Ser. No. 14/161,925, filed on Jan. 23, 2014, and all incorporated herein by reference.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art and copending applications.
Accordingly, it is an object of the present invention to provide new and improved methods for the growth of single crystal III-N semiconductor material on a silicon substrate.
It is another object of the present invention to provide new and improved methods for the growth of single crystal III-N semiconductor material on a silicon substrate using an improved template.
It is another object of the present invention to provide new and improved methods for the formation of a nucleation layer for the growth of single crystal III-N semiconductor material.